Using the tick event I setup a simple graph that added the delta time to a variable, and once it was above 0 I started the sound and then the getspectrum calls.
I did notice some issues with timing though, and based on the helpful reply from JamesG above I’ll try his approach 
You can also control the sample length when calculating, and for some visuals (bars going up and down) I found it helpful to smooth out the peaks by going for a slightly longer time than the tick.